#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>


int main (int argc, char *argv[]) {
	// getpid是unistd中那个吗 我没有include unistd.h 也ok，为啥？
	// 有人说有些编译器会自动链接标准库  https://stackoverflow.com/questions/60127820/i-have-not-included-unistd-h-head-file-why-still-invoke-function-getpid-suc
	long pid = (long)getpid();
    long test = pid + 1;
	printf("Current process pid is:%ld\n", pid);
	exit(0);
}
